MONTPELIER — Entergy Nuclear has wasted no time in quickly filing an amended petition with the Public Service Board seeking to operate Vermont Yankee until Dec. 31, 2014.

Entergy currently has an already amended petition pending before the Public Service Board, which is expected to make a decision later this year on whether the company gets a certificate of public good.

Until Tuesday, when Entergy Corp. announced it was closing the Vermont Yankee plant due to low power prices, Entergy was seeking state permission to operate for another 20 years.

“I think they wanted to show they were serious about their decision,” said Chris Recchia, commissioner of the Department of Public Service, which represents Vermont consumers before the quasi-judicial board.

Entergy lawyers filed the amended petition with the board late Tuesday afternoon. Entergy executives said the decision to close Vermont Yankee during the fourth quarter of 2014 had been made Sunday night by the Entergy Board of Directors.

“We’re still evaluating what the best process would be to get through the CPG,” said Recchia, referring to the state approval process.

“It’s interesting they did it so quickly,” he said.

In the new petition, Entergy asserts that it doesn’t need additional approval from the Public Service Board for the continued storage of spent nuclear fuel, something Entergy officials at a press conference Tuesday had been vague about.

“If this Board disagrees, Entergy VY seeks such approval, while reserving its right to argue to the Board and any reviewing court that Entergy VY does not need such approval,” the petition read.

“Entergy VY respectfully requests that the board find that the operation of the VY station after March 21, 2012 and until December 31, 2014 will promote the public good and issue a CPG,” the petition said.

The petition makes no mention that Entergy had decided to shut down Vermont Yankee.

Vermont Yankee received permission from the Public Service Board in 2006 to build its dry cask storage facility, where giant concrete and steel casks hold some of Yankee’s highly radioactive spent fuel assemblies.

Currently there are about 1,500 spent fuel assemblies remaining in Yankee’s spent fuel pool which would have to be moved into so-called “dry cask” storage once the fuel has been allowed to cool down, a period of about five years.

Entergy Nuclear spokesman Jim Sinclair did not respond to an email about the latest filing.

The four-page filing mentions in several areas the decision by the 2nd Circuit Court of Appeals two weeks ago that upheld a decision by U.S. District Judge J. Garvan Murtha that two Vermont laws were illegal because they tried to usurp the powers of the Nuclear Regulatory Commission over the issue of safety at nuclear power plants.

Entergy had filed its first amended petition in March 2012, after Murtha’s decision, which upheld the right of the Vermont board to review other aspects of Vermont Yankee’s operation.

The 2nd Circuit said that the federal Atomic Energy Act preempted both Vermont’s Act 74 and Act 160, which had given the Vermont Legislature veto power over Vermont Yankee’s operation.

“I guess in the big picture I’m not surprised by the outcome. I wonder why they hadn’t made this decision before 2012,” said Recchia, about the certificate of public good process.

“We’re trying to wind this down in a way that is good for Vermonters,” said Recchia.

Recchia, echoing statements made by Gov. Peter Shumlin Tuesday, said that the state would “engage in a positive way” with Entergy on planning the decommissioning of Vermont Yankee. Entergy officials want to mothball Vermont Yankee for 60 years, a process called Safestor, while Vermont officials want a much quicker dismantling of Yankee and cleanup of the Vernon site, allowing it to be redeveloped.

The amended petition was filed by Nancy Malmquist and John Marshall of Downs Rachlin Martin.